Abstract: A water-based ink for ink-jet recording includes: a water-soluble colorant; water; a water-insoluble liquid; a nonionic surfactant; and an ionic surfactant having a polarity same as that of the water-soluble colorant. The water-insoluble liquid is dispersed stably in the water by the nonionic surfactant and the ionic surfactant having the polarity same as that of the water-soluble colorant.

Abstract: A water-based ink for ink-jet recording includes: a pigment; water; 1,2-alkanediol; and a surfactant represented by the following general formula (1): R1CON(CH3)CH2CH2R2, wherein in the general formula (1), R1 is a saturated or unsaturated hydrocarbon group having 9 to 19 carbon atoms; the hydrocarbon group is straight chain or branched chain hydrocarbon group; R2 is SO3M or COOM; and M is Li, Na or K.

Abstract: A water-based ink for ink-jet recording includes: a water-soluble colorant; water; a water-insoluble liquid; a nonionic surfactant; and an ionic surfactant having a polarity same as that of the water-soluble colorant. The water-insoluble liquid is dispersed stably in the water by the nonionic surfactant and the ionic surfactant having the polarity same as that of the water-soluble colorant.

Abstract: A water-based ink for ink-jet recording includes a pigment; water; 1,2-alkanediol; a compound including an isothiazoline ring; and a surfactant represented by a general formula (1): In the general formula (1); each of R1, R2, R3, and R4 is one of a hydroxyl group, saturated fatty acid having a number of carbon atoms of 12 to 18 and unsaturated fatty acid having a number of carbon atoms of 12 to 18; and a, b, c, and d are identical with each other or different from each other, and a, b, c, and d are numbers to fulfill a+b+c+d?20.

Abstract: A water-based ink for ink-jet recording includes: a water-soluble colorant; water; a water-insoluble liquid; a nonionic surfactant; and an ionic surfactant having a polarity same as that of the water-soluble colorant. The water-insoluble liquid is dispersed stably in the water by the nonionic surfactant and the ionic surfactant having the polarity same as that of the water-soluble colorant.

Abstract: A water-based ink for ink-jet recording includes a pigment; water; 1,2-alkanediol; a compound including an isothiazoline ring; and a surfactant represented by a general formula (1): In the general formula (1); each of R1, R2, R3, and R4 is one of a hydroxyl group, saturated fatty acid having a number of carbon atoms of 12 to 18 and unsaturated fatty acid having a number of carbon atoms of 12 to 18; and a, b, c, and d are identical with each other or different from each other, and a, b, c, and d are numbers to fulfill a+b+c+d?20.

Abstract: A water-based ink for ink-jet recording includes: a pigment; water; 1,2-alkanediol; and a surfactant represented by the following general formula (1): R1CON(CH3)CH2CH2R2, wherein in the general formula (1), R1 is a saturated or unsaturated hydrocarbon group having 9 to 19 carbon atoms; the hydrocarbon group is straight chain or branched chain hydrocarbon group; R2 is SO3M or COOM; and M is Li, Na or K.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate group-modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains a monovalent metal ion, water, and a water-soluble organic solvent.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate-group modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains an aggregating agent, water, and a water-soluble organic solvent. A dynamic surface tension of the water-based ink, measured under the condition where a life time is about 50 ms, is in the range of 35 mN/m to 45 mN/m. A dynamic surface tension of the treatment liquid, measured under the condition where a life time is about 50 ms, is in the range of 33 mN/m to 45 mN/m.

Abstract: An ink for ink-jet recording includes a luminescence marker which emits light by oxidization. It may be determined whether the ink for ink-jet recording is used for recording the ink-jet recorded object with a simple method such as an evaluation of luminescence by oxidation, without requiring a special equipment.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one of a reducing sugar and a sugar alcohol and a calcium ion.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one selected from the group consisting of boric acid, diglycolic acid, and a chelating agent.

Abstract: A water-based ink for ink-jet recording includes a coloring agent, water, and a water-soluble organic solvent. The coloring agent includes the following dye (1) and dye (2). The water-based ink is good in clearness, color development, and preservation stability as well as good in toughness of a recording material recorded using the water-based ink. Dye (1): dye represented by the following general formula (1) Dye (2): at least one dye selected from the group consisting of C. I. Direct Yellow 86, C. I. Direct Yellow 132, C. I. Direct Yellow 142, and C. I. Direct Yellow 173.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate-group modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains an aggregating agent, water, and a water-soluble organic solvent. A dynamic surface tension of the water-based ink, measured under the condition where a life time is about 50 ms, is in the range of 35 mN/m to 45 mN/m. A dynamic surface tension of the treatment liquid, measured under the condition where a life time is about 50 ms, is in the range of 33 mN/m to 45 mN/m.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate group-modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains a monovalent metal ion, water, and a water-soluble organic solvent.

Abstract: A water-based ink for ink-jet recording includes a self-dispersing pigment, water, a water-soluble organic solvent, and an acetylene glycol surfactant. An amount of the self-dispersing pigment (solid content) relative to a total amount of the ink is in a range of about 3.5 wt % to about 4.5 wt %. The water-soluble organic solvent includes glycerin and dipropylene glycol propyl ether, an amount of the glycerin relative to a total amount of the ink is in a range of about 15 wt % to about 25 wt %, and an amount of the dipropylene glycol propyl ether relative to a total amount of the ink is in a range of about 2.0 wt % to about 3.0 wt %. An amount of the acetylene glycol surfactant relative to a total amount of the ink is in a range of about 0.1 wt % to about 0.3 wt %.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one selected from the group consisting of boric acid, diglycolic acid, and a chelating agent.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one of a reducing sugar and a sugar alcohol and a calcium ion.

Abstract: A water base ink for ink-jet recording contains a self-dispersible coloring agent, a propylene glycol ether, and a surfactant represented by the following general formula (3): R1—O—(CH2CH2O)n—SO3M??(3) wherein R1 represents an alkyl group having a number of carbon atoms of 12 to 15, M represents Na or triethanolamine, and n represents an integer of 2 to 4, and wherein the propylene glycol ether is dipropylene glycol propyl ether. The ink satisfies three requirements of i) the satisfactory initial introduction performance of the ink into an ink flow passage of a stacked type printer head, ii) the prevention of the occurrence of feathering, and iii) the prevention of the insufficient spread of the ink.

Abstract: The invention relates to an ink-jet recording apparatus having a nozzle provided on a nozzle face of an ink-jet head and a cleaning device for cleaning the nozzle face. The cleaning device contains a gas with a solubility in water lower than that of air in water.